A new study brings bad news for people fighting bedbug
infestations and companies that sell over-the-counter
insecticides.

Ohio State University entomologists Susan Jones and Joshua Bryant
found that "bug bombs" and "foggers" - cheap, insecticide-spraying
aerosols that have been marketed for decades as do-it-yourself
alternatives to exterminators - were ineffective against even the
most vulnerable of bedbugs.

In the study, published last month in the Journal of Economic
Entomology, the researchers tested three popular commercial foggers
against five wild strains of bedbugs found in Ohio homes and one
laboratory strain that had not been exposed to insecticides.

They found that after spraying the bugs with a typical two-hour
fog, only the laboratory bugs had died; nearly all of the wild
bedbugs, though placed in completely exposed containers, had
survived. When the scientists covered the containers with paper to
simulate the bedding that the insects often nest in, nearly all the
bedbugs from every strain survived - even the laboratory
strain.

The scientists concluded not only that most wild bedbugs are
resistant to pyrethroids, the active ingredients in fogger
aerosols, but also that the fogging process itself is fundamentally
flawed.

"The spray can't penetrate through a thin paper sheet, much less
into cracks and crevices where bedbugs hide in real life. On top of
that, we're dealing with bugs resistant to pyrethroids in the first
place" said Jones. "It's a death knell for this type of
product."

Jones, who had initially designed the study to test whether foggers
caused surviving bedbugs to scatter and inhabit previously
uninfested areas, said the results were so unexpectedly poor that
she had to backtrack and ask whether these products worked at
all.

"After we ran the first spraying experiments, we saw that the bugs
were crawling around as if nothing had happened,'" she said.

The study tested two general-use products, Spectracide Bug Stop
Indoor Fogger and Eliminator Indoor Fogger, and one marketed
specifically for bedbugs, called the Hot Shot Bedbug and Flea
Fogger. All three were developed by Spectrum Brands.

Missy Henriksen, a spokeswoman at the National Pest Management
Association, said that Jones and Bryant's results "could be new for
consumers but weren't a surprise to the professional
pest-management industry."

University of Kentucky entomologist Kenneth Haynes, who wasn't
involved in the study, said that academics have not held stock in
foggers for years.

"I don't view bedbugs as a do-it-yourself project, and I'd call an
exterminator if I had them - even though I know quite a lot about
the bugs," Haynes said.

Asked for comment, Spectrum provided an e-mail statement saying
that the Hot Shot fogger "has been thoroughly tested and is proven
to be effective against the bedbugs they contact."

Bedbug infestations have been on the rise since the ban of
DDT in 1972, due in part to increased international travel and the
evolution of bedbug resistance to weaker insecticides. The bugs can
be dragged into homes and offices on clothing, luggage, used
furniture and pets - especially after trips to summer camps or
foreign countries.

Once they arrive, adult bedbugs can survive for more than half a
year without feeding on blood from a human or other warm-blooded
animal.

"That's bedbug biology. They have evolved to be very good at hiding
and waiting to home in on the next blood meal," Henriksen
said.

Haynes said that foggers, in addition to fueling increased bedbug
resistance to insecticides, can pose dangers to people.

In 2008, the Centers for Disease Control and Prevention reported
466 cases of acute, pesticide-related illness or injury associated
with exposure to foggers between 2001 and 2006 in eight states. The
study noted that harm often occurs when users leave fogged rooms
too late, re-enter too early, don't wipe down sprayed surfaces or
use flame nearby. (Pyrethroids are extremely flammable.)

Jones said she hoped the Environmental Protection Agency would
review manufacturers' efficacy data about these products and
investigate which bedbug strains were used to test their
products.

For consumers, she said that a sharp eye around the house and a
habit of running linens in the high heat dryer cycle are far more
effective at keeping the unwelcome critters at bay than foggers
are.